This invention relates to hot air furnaces, and particularly to furnaces having hot water radiators in their plenums to increase the efficiency of the furnaces.
Presently, heating systems in homes most commonly use compact hot air furnaces that use either gas or oil as fuel. To increase the efficiency of the furnaces, the amounts of heat escaping with exhaust gases up the flues must be minimized. Certain systems such as that shown in U.S. Pat. No. 3,916,991 issued to George S. Trump on Nov. 4, 1975 use an extended flue with heat exchangers connected therewith for obtaining heat for the home from the flow of exhaust gas.